This invention relates to portable water purifiers, their method of making and their method of use.
Converting water containing chemical and/or biological contaminants into potable water is a challenge often encountered by individuals such as hikers, campers, and soldiers, who do not have access to dean drinking water when in the field. Extended periods of outdoor travel on foot in areas where there is no known clean water source necessitates an effective water purification system that is lightweight, self-contained, and can easily be carried on the person. Furthermore, the ability of a water purification system to remove both chemical and biological contaminants may be critical when the only available water source is industrial waste water or water generated by a septic system.
A variety of portable water purification systems are available; however, such systems are often significantly limited in terms of portability and effectiveness. Most commercially available water purification systems typically include a manual pump which, through the use of air pressure, forces water through a column containing a filtration device. Often, the pump and filtration device is separate from and external to a water receptacle; therefore, the user is required to carry the pump and filtration device as well as a suitable receptacle for the purified water. In addition to the issue of portability, the use of air pressure to force contaminated water through a filtration device may greatly decrease the effectiveness of the filtration device. Using a pump that operates by air pressure means may result in the formation of air pockets within the filtration device. Removing common biological contaminants such as Giardia and Cryptosporidia can be particularly problematic if such air pockets form within the filtration system. Air pockets in the filtration device are likely to prevent biological organisms from contacting the filtration material, thereby allowing viable infectious organisms to pass through the filter and into the water that is to be consumed. Thus, there is a need for a water purification system that includes a pump and filtration device that is integrated with a water receptacle. Likewise, there is also a need for a water purification system that utilizes water pressure rather than air pressure to force water through a filtration device.
The filtration devices found within many commercial water purification systems are designed to remove either chemical contaminants such as pesticide residues, or biological contaminants such as those already mentioned. However, many of these systems are not designed to effectively remove both chemical and biological contaminants from a water source. Furthermore, the effectiveness of the filtration devices employed by many commercially available water purification systems can be highly variable due to problems with both the materials used for filtration and with the overall construction of the devices. Thus, there is a need for a water purification system that consistently and effectively removes both chemical and biological contaminants.
Two U.S. patents disclose water filtration systems that are integrated with water receptacles, but each system is subject to significant limitations. U.S. Pat. No. 4,714,550 to Malson-Sharpe discloses a water purifying system designed to be mounted in a conventional canteen. The user must first fill the canteen with contaminated water, and then insert the purifier into the canteen. This system employs a pump that utilizes air pressure to force the contaminated water contained in the canteen body through a filtration resin and eventually into a straw-like conduit from which the user consumes the water. The design of the Malson-Sharpe system has several significant drawbacks. Firstly, filling the body of the canteen with contaminated water provides an environment in which pathogenic microorganisms may incubate and multiply. Thus, if a person does not insert the purifier every time the canteen is used, or does not thoroughly clean the interior of the canteen between uses, that individual runs the serious risk of consuming water containing infectious bacteria or other microorganisms. Secondly, this system utilizes air pressure to pump water through the purifier, which as described above, can result in a marked decrease in the effectiveness of the filtration system. U.S. Pat. No. 5,167,819 to Iana-McCray also employs a filtration device is that is inserted into a canteen filled with contaminated water. This device utilizes suction applied by the user, rather than a manual pump, to draw water through a filter. Again, the use of air pressure to force water through the filter results in the potential reduction of the effectiveness of the filter. Finally, the water purification systems taught by U.S. Pat. Nos. 4,714,550 and 5,167,819 both require the user to consume purified water from an outlet located very close to the inlet for the contaminated water. The proximity of the water inlet to the water outlet may result in the inadvertent or accidental consumption of unfiltered water containing infectious, pathogenic microorganisms or toxic chemicals. Thus, there is a need for a portable water filtration system in which the water inlet and water outlet are separated by a distance sufficient to prevent the accidental ingestion of contaminated water.
Accordingly, these and other disadvantages of the prior art are overcome by the present invention, which provides a water purification apparatus comprising an integrated filtration device and sealable receptacle for storing purified water. This invention converts undrinkable water into potable water, is fully self-contained, removes chemical and biological contaminants, and is small enough to be conveniently carried into the field by a hiker, camper, or soldier. The present invention further includes a canteen body specially modified to receive a well in which a filtration assembly is secured. The filtration assembly includes a pump and a multistage filter cartridge. The multistage filter cartridge is removable and replaceable and includes a two-stage porous material and purification resin filter, or a three-stage porous material, purification resin, and carbon filter. The pump of the filtration device utilizes water pressure, rather than air pressure, to force contaminated water through the multistage filter cartridge. Utilization of water pressure eliminates, or greatly reduces, the formation of air pockets within the multistage filter cartridge, thereby mitigating the risk of decreased filter effectiveness. The clean water receptacle of this invention also provides a first opening for water intake and a second opening for water outflow so that the user need not drink from the same opening through which contaminated water entered the body of the canteen. Additionally, the canteen body of this invention provides a sealable receptacle in which a volume of water can be stored following purification, thereby eliminating the need to ever introduce chemically or biologically contaminated water into the body of the canteen where it could be accidentally or inadvertently consumed by the user.
Further objects and advantages of the present invention will become apparent from a consideration of the drawings and subsequent detailed description of this invention.